Rep. Jesse Jackson Jr. of Illinois resigned this week, and the Chicago press is already abuzz about who will fill the seat. One Democrat has said the seat could flip parties, though that seems unlikely.

Rep. Jesse Jackson Jr. (D) of Illinois and his wife, Chicago Alderman Sandi Jackson, ask each other for their support and votes as they arrive at a polling station for early voting in Chicago in March. Congressman Jackson resigned Wednesday.

Chicago — The congressional seat vacated by Rep. Jesse Jackson Jr. this week is attracting no small amount of interest.

Since Jackson announced on Wednesday that he was leaving office after 17 years for mental-health reasons, the local media have cited a number of sources saying they want to represent Illinois' Second District. They include his wife, Chicago Alderman Sandi Jackson; his brother, John Jackson; and former US Rep. Debbie Halvorson, who lost to Congressman Jackson in the March Democratic primary.

Some Democrats see a danger in so many would-be members of congressman. “My fear is that there is going to be so many wannabes blinded by ambition ... that we could find a tea party" candidate winning, said Rep. Bobby Rush, who represents Illinois' First District, hours after Jackson’s resignation.

With President Obama taking 82 percent of the vote in the Nov. 6 election, that would seem a remote prospect. Whoever advances from the Democratic primary would seem to be the overwhelming favorite.

Still, independent candidate Marcus Lewis has already announced his candidacy. He lost to Jackson in November, taking only about 14 percent of the vote. He made his intentions known late Wednesday, telling supporters he planned to run “to stop the trickery” associated with the seat “for decades.”

In his resignation letter sent to House Speaker John Boehner Wednesday, Jackson noted that he was also preparing for a federal indictment that media reports say should be announced against him in the near future. The House Ethics Committee is investigating whether Jackson tried to bribe imprisoned Governor Blagojevich for an appointment to Mr. Obama’s former Senate seat, or at least tried to engage in the process through an emissary. Jackson denies the charges.

“I am doing my best to address the situation responsibly, cooperate with the investigators, and accept my responsibility for my mistakes, for they are my mistakes and mine alone,” Jackson wrote.

Since Jackson submitted his letter, Ms. Halvorson says her phone has been ringing. Supporters and other local leaders urging her to run, she says. She represented Illinois' 11th District for one term before losing two years ago. This year, she lost to Jackson 71 to 29 percent in the Second District primary.

“This district has been so underrepresented, and not just over the last six months, it’s been a long time. You can’t have somebody going into this seat with a learning curve,” she says.

Most people felt Jackson would wait until after the Christmas holiday to resign, Halvorson says. She said the timing put her “in a crazy spot” in which she’ll have to “figure out what is in the best interest of the district.”

“I never thought I would be at this again, but we also have another 100 days,” she says. "We have to prove that honor needs to be put back into the seat and that being a member of Congress is an admirable position. We have work cut out for us.”

On Monday, Illinois Gov. Pat Quinn is expected to announce the date for a special election that he promised will be “as economical as possible for taxpayers.” Estimates by the Illinois State Board of Elections suggest it will cost about $5.15 million for both a primary and a general election.

The special election date must fall within 115 days of the vacancy. Cook County Clerk David Orr said he fellow county clerks are urging Quinn to schedule the special election for April 9, with a primary on Feb. 26, in order to coincide with election dates in suburban areas, according to the Chicago Sun-Times.

Mr. Orr warned candidates against making announcements or circulating petitions before the election date is set.

“People can always be talking to voters, there’s nothing to stop them from that, but at this point I would not encourage petition gathering until we have a better handle on this,” he said.

The Second District covers portions of Will and Kankakee Counties and southern Cook County, including the South Side of Chicago.